Implantable medical devices, such as cardiac pacemakers, defibrillators, deep brain stimulators, spinal cord stimulators, vagus nerve stimulators, stomach stimulators, muscle stimulators, or peripheral nerve stimulators, are widely used for disease therapy.
The implantable medical device can generate electrical stimulation pulses and apply the electrical stimulation pulses to the target nerve tissue of the patient to treat a disease. Usually, the implantable medical device stimulates the target nerve tissue at a constant frequency for a long time, such as several days, several months, or even several years, and that is called constant frequency stimulation mode. However, the constant frequency stimulation mode has a low efficacy for some disorders and would result in adaptability to stimulation therapy. In the case of patients suffering from Parkinson's disease (Parkinson patients) for example, deep brain stimulation at constant frequency stimulation mode has little treatment efficiency on some non-motor symptoms, such as dysarthria, dyskinesia or freezing of gait. For Parkinson patients and some epilepsy sufferers, it is easy to adapt to the electrical stimulation of the nerves at constant frequency stimulation mode, like constant exposure to a drug results in resistance to the action of the drug and treatment can be ineffective.
An electrical stimulation testing device can be used to test whether a patient is suitable for the electrical stimulation therapy. However, an electrical stimulation testing device only has the constant frequency stimulation mode.
What is needed, therefore, is to provide an electrical stimulation therapy method and an implantable medical device which can overcome the shortcomings as described above.